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    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <script>
        let str = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'

        let cites = 
            [{
                py: 'beijing',
                name: '北京'
            },
            {
                py: 'alishan',
                name: '阿里山'
            },
            {
                py: 'beidaihe',
                name: '北戴河'
            },
            {
                py: 'shijiazhuang',
                name: '石家庄'
            }]
        let obj ={};
        str.split('').forEach(function(item){
            obj[item] = [];
            console.log(obj);
        });
        cites.forEach(function(item){
            obj[item.py.slice(0,1).toUpperCase()].push(item)
        });
        console.log(obj);
    </script>
</body>

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